Dating fraudsters conned thousands of victims out of more than £33 million last year, figures have revealed.
Police disclosed that 3,543 people reported they had been targeted by romance scams in 2014/15, with a total financial loss of £33,650,491.
Commander Chris Greany, the police national co-ordinator for economic crime, described the losses as "colossal" and warned that this type of criminal activity is on the rise. He also appealed to those who feel too embarrassed to report their experiences to police to come forward.
Action Fraud and City of London Police have launched a 13-day campaign to identify common myths around fraud and cyber crime.
They said one example was the belief that users of dating websites are vetted before they are allowed to have a membership, when this is "very rarely" the case.
Mr Greany said of romance fraud: "It is a reprehensible criminal act which preys on one of the oldest human emotions, which is love."
The most recent data showed a 9% jump in fraud offences reported to authorities, while crime surveys indicated that on average one in 12 adults has experienced fraud and one in 22 is a victim of cyber fraud.
"Fraud does seem to be on the increase, and with dating fraud we can definitely say it has gone up in the last year," Mr Greany said.
Sums stolen in scams range from small to "huge" amounts, he said, and urged those looking for love not to send money to people they meet through dating sites.
"Dating websites are all good and sometimes they help people find partners but people need to be circumspect about what they find," Mr Greany added.
"We say to people yes, go on dating websites, be circumspect, but what you must never do is send money to people.
"There are some very tragic examples where people have sent everything they have and now they have got nothing."
Mr Greany also suggested that people could use online tools to check if images of their love interest are genuine.
"I always say if it looks too good to be true, it's probably fraud," he told the Press Association.
Police believe a substantial proportion of dating fraud goes unreported, in part because some victims are too embarrassed.
Mr Greany urged them to come forward as their information is crucial in helping to track down the "reprehensible" criminals responsible.
He added: "We have really well-trained call handlers, really compassionate and understanding. Don't be embarrassed to speak to us.
"We want to understand the entirety of what is happening and we can only do that if people come forward."
A number of cases have highlighted the risk of dating fraud.
Last year four men were jailed in connection with a dating website scam which targeted single women looking for love online and saw victims hand over a total of £220,000.
Earlier this month a Bentley-driving lonely hearts fraudster was jailed for eight years for conning five women, including an elderly widow, out of almost £200,000.
Car salesman Matthew Samuels, 50, of Worcester, was said by a judge to have caused "incalculable" damage to a bereaved victim who handed him money from an inheritance.
He was also convicted of duping the mother of a woman he met online with a bogus promise of a Wimbledon debenture.